From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Simmons Date: Sun, 21 Jul 2019 21:23:31 -0400 Subject: [lustre-devel] [PATCH 02/22] ext4: use d_find_alias() in ext4_lookup In-Reply-To: <1563758631-29550-1-git-send-email-jsimmons@infradead.org> References: <1563758631-29550-1-git-send-email-jsimmons@infradead.org> Message-ID: <1563758631-29550-3-git-send-email-jsimmons@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org From: James Simmons Really old bug that might not even exist anymore? Signed-off-by: James Simmons --- fs/ext4/namei.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index cd01c4a..a616f58 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1664,6 +1664,35 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi } } + /* ".." shouldn't go into dcache to preserve dcache hierarchy + * otherwise we'll get parent being a child of actual child. + * see bug 10458 for details -bzzz + */ + if (inode && (dentry->d_name.name[0] == '.' && + (dentry->d_name.len == 1 || (dentry->d_name.len == 2 && + dentry->d_name.name[1] == '.')))) { + struct dentry *goal = NULL; + + /* first, look for an existing dentry - any one is good */ + goal = d_find_any_alias(inode); + if (!goal) { + spin_lock(&dentry->d_lock); + /* there is no alias, we need to make current dentry: + * a) inaccessible for __d_lookup() + * b) inaccessible for iopen + */ + J_ASSERT(hlist_unhashed(&dentry->d_u.d_alias)); + dentry->d_flags |= DCACHE_NFSFS_RENAMED; + /* this is d_instantiate() ... */ + hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); + dentry->d_inode = inode; + spin_unlock(&dentry->d_lock); + } + if (goal) + iput(inode); + return goal; + } + #ifdef CONFIG_UNICODE if (!inode && IS_CASEFOLDED(dir)) { /* Eventually we want to call d_add_ci(dentry, NULL) -- 1.8.3.1